Re: select function alias

From: "Howard News" <howardnews@selestial.com>
Sent: Wednesday, November 30, 2016 9:03:28 AM
Subject: Re: [GENERAL] select function alias

On 30/11/2016 13:42, Timoteo Blanco wrote:

I've a series of timestamp columns I'd like to alias in select statements. psql indicates my alias doesnt exist after 

I define it. 

Example -> select to_char(impressions_create_date,'yyyy-mm-dd') as ymd from impressionsdb where ymd like '2016-11%' ;

psql always complains column ymd does not exist. I've inherited a series of tables with many timestamps and would like to 

shorten the select in queries without renaming any columns.

3 options:

1. Use the same to_char expression in the where clause
2. Use a sub-select to use the alias in the outer where clause
3. Use the original column in the where clause and use the timestamp comparisson functions.